This invention relates to instruments for effecting aspiration and irrigation during ophthalmic surgery.
Numerous aspiration-irrigation systems useful in ophthalmic surgery have been proposed. The mechanically powered systems thus far introduced are generally quite expensive and have a number of disadvantages. Several manual systems have been in limited use. Among these are the Fuch's two-way syringe (see Am. J. Ophthal., 3:1264-0,1971) and the Fink-Weinstein two-way syringe (see Am. J. Ophthal., 58:129-30, 1964). These are manual pumping systems with double-lumen cannulae attached. They allow the surgeon to manually pump fluid from the irrigation system to the aspiration system with the resultant pickup of dissolved or dispersed material. The O'Gawa syringe (see Am. J. Ophthal., 64:970, 1967) has two separate and parallel lumen, thus allowing aspiration and irrigation through separate channels. It was designed for syringe aspiration by a surgical assistant who is necessarily remote from the operating field. Its major disadvantage is the difficulty of precise aspiration control inherent in the time lag between the surgeon and his assistant. Generally speaking, the manual systems proposed to date are rather complex in their design and manufacture and somewhat cumbersome to use, disassemble, clean, sterilize and reassemble.
It is an object of the present invention to provide a compact, uncomplicated instrument for effecting aspiration and irrigation during ophthalmic surgery that is simple to operate, disassemble, clean, sterilize and reassemble and inexpensive to manufacture. It is a further object to provide such an instrument having two telescopically disposed cannulae, each of which can be quickly and easily separated from the other (and from the remainder of the instrument) and quickly and easily replaced by another cannula having, for example, a different tip configuration or bore size. It is a further object to provide an instrument of the type described in which the cannulae define separate, substantially concentric passages for supplying fluid to and withdrawing fluid from the surgical site.